dude, so easy to make.... ya gotta do these. Layer 'em and stick 'em in the oven for about 25 minutes at 200 degrees to get 'em toasty and melty. Tent some aluminum foil over them to keep them from getting too crispy.
Traditionally, they were served cold, but warming them has been part of the evolution of the sandwich. I mean, how can anyone ague with melty cheese, toasty bread, and warm dripping olive oil?